Brainstem taste nuclei seem to process information according to well-established principles governing the coding of gustatory quality and intensity. Forebrain tissue neurons, however, give responses which suggest that they are not sensitive to the same stimulus parameters, nor do they respond according to the same principles as brainstem cells. From evidence provided by other investigators, we suspect that thalamic taste neurons are sensitive not only to the same stimulus parameters, nor do they respond according to the same principles as brainstem cells. From evidence provided by other investigators, we suspect that thalamic taste neurons are sensitive not only to the transient activity produced by chemical stimulation of the tongue, but also to other factors such as the internal milieu of the body and olfactory and somesthetic input. We plan to record from thalamic and other forebrain sites in rats which are neither anesthetized nor paralyzed. Subjects will be restrained but relaxed and will have access to their own liquid (taste) supply during recording. We will then vary any of several parameters: fluid deprivation, hunger, conditioned aversions and olfactory stimulation to see how they affect responses to chemical stimulation of the tongue.